1. Field of Invention
This invention relates to weapons fire control systems. Specifically, the present invention relates to systems for effecting boresight alignment for TOW (tube launched, optically tracked, wire-guided) missile fire control systems.
2. Description of the Related Art
The there is an ongoing need to increase the accuracy and performance of missile fire control systems. Efforts to obtain greater target percentages have led to the development of devices such as laser target designators. As targeting hardware becomes more sophisticated, the need increases for advanced electrical subsystems. This is particularly true of the TOW missile system. TOW missiles are relatively inexpensive, tube-launched, optically tracked wire-guided missiles. The electrical subsystems of conventional TOW missiles are not designed to be compatible with new devices such as laser target designators. In addition, the analog fire control circuitry for the TOW missile is over 20 years old. As a result, components necessary for replacement are becoming increasingly difficult to obtain.
In addition, conventional TOW fire control circuitry is plagued with noise. This noise, referred to as angular noise, obscures important signals in the feedback control loop which are largely responsible for missile accuracy and boresight alignment.
Efforts to reduce the effects of the angular noise led to analog filtering of the noise during boresight alignment. Noise filtering was limited due to stability requirements of the boresight control loop. In the existing fire control electronics, angular noise is still responsible for as much as 5.5 to 12.4 microradians of uncertainty.
Hence, a need exists in the art for a versatile TOW fire control system which reduces the effects of angular noise and is compatible with current technology.